Lambda / NOX sensor

What does a NOX sensor do?

In a NOX sensor, the NOX is separated into nitrogen and oxygen by a catalytically active electrode.
The amount of oxygen is measured in the same way as with a broadband or linear lambda sensor.

Lambda probe

A lambda sensor is a sensor located in the exhaust of a car with a petrol engine that measures the proportion of oxygen in the exhaust gas and passes it on to the engine management system. The lambda value is an indicator of the effectiveness of combustion. Depending on the lambda value, this is adjusted by the engine management system by adjusting the composition of the fuel and air ratio by adjusting the fuel injection, by changing the injection time of the injectors.

Vehicles after the year 2000 have a second oxygen sensor behind the catalytic converter to check its effectiveness.

The probe

The sensor element is a ceramic cylinder, coated inside and out with porous platinum electrodes; the whole is protected by a metal mesh. It works by the difference in oxygen between the exhaust gas and the outside air and generates a voltage or changes its resistance, depending on the type of sensor.

The sensors are only effective when heated from about 316 ° C; that is why most oxygen sensors have a heating element that quickly warms the ceramic tip. This allows a faster control of the blend composition. Older probes without heating elements are heated by the exhaust gases, but there is a longer period between the moment the engine is started and the moment the probe is at the right temperature. Without heating, the process can take a few minutes.

The probe usually has four wires, one signal wire, usually black, one ground wire (gray) and two for the heating element (white). Older non-electric heated sensors had one wire (the signal wire and ground through the outlet) or two wires (one signal wire and one ground wire).

Lambda signal

The signal from the probe for the catalyst varies from 0,1 to 0,9 volts at resp. an arm or a rich mixture. In stoichiometric combustion of gasoline this is 0,45 V, the lambda value is then 1.

Issues

It happens more and more often that problems occur in the operation of the 2nd Lambda. Chip Performance can rewrite the software so that this 2nd sensor is disabled, so that your car functions optimally again. If you have problems with the Lambda sensor, please contact us about the possibilities we can offer you.

With the following brands and models it is possible to switch off the lambda, 2de lambda or NOX sensor. If your model does not exist, please contact with us!